yii2 form afterValidate?

YII 1.x

    <?php $form = $this->beginWidget(CActiveForm', array(


        'id' => 'loginForm',


        'enableClientValidation' => true,


        'clientOptions' => array(


            'validateOnSubmit' => true,


            'afterValidate' => 'js:function(form,data,hasError){


                    if(!hasError){


                        login( $("#loginForm") );


                        return false;


                    }}'


        ),


    )); ?>

YII2 ?

How Ajax submit form